How to regain some performance on old skis?

I have a 99 Genisis FI (175 hours) and a 2001 Virage FI (155 hours) unit. While they both still run well, the Genisis is down 3-4 mph from new and the Virage 4-5mph. I installed upgraded intakes when new (I bought them both new in 2001) and last year put in new plugs and fuel lines.

Is this just the result of getting old (like me), or is there any other things I can do to restore some of the missing performance. The Genisis runs around 54-55mph now according to dash readout and the Virage 56-57mph. When new I gps them with my bass boat and the dash readouts were both slow by 1+ mph, with the Genisis running 58-59 and the Virage running right close to 61-62mph. Thx.

What sustained engine RPM is each running at wide open throttle on smooth water? Press the Display button to show RPM tachometer numbers along the bottom edge of display.

Engine RPM is a better indicator of engine health than speedometer numbers.

The Virage is a two cylinder Ficht engine, correct?

Inspect the jet pump on each watercraft. Look for dings and other imperfections in the impeller blades. While it is easiest to inspect when the jet pump is removed, you can shine a flashlight in through the intake grate to see the impeller.

The gap between the outside edges of the impeller blades and the surrounding wear ring is important. A good condition jet pump will measure about .010" or less. A worn impeller or worn wear ring that exceeds .020" gap is considered excessive.

Also inspect the jet pump stator. Look for damage to the fixed vanes.

The speedometer works on water pressure from a pitot fin, located just inside the intake grate. Make sure this fin is aligned with the water flow and is undamaged, with no blockage of the small hole in the leading edge.

Inside the hull is a clear tube leading from the pitot to the back of the display. This flexible tube must be unobstructed and not kinked along its entire length and snugly fitted to the small plastic nipples at each end. The nipple under the driveshaft is fragile, do not flex or stress it.